Republicans had been hesitant to accept President Obama’s invitation to participate in Thursday’s White House health-care summit. Their hesitance turned out to be justified.

An equal number of Democratic and Republican lawmakers assembled around a table at Blair House, and each had a chance to speak during the seven-hour televised talkathon. But members of the opposition party may not have fully understood that they were stepping into Prof. Obama’s classroom, and that they were to be treated like his undisciplined pupils.

Obama controlled the microphone and the clock, and he used both skillfully to limit the Republicans’ time, to rebut their arguments and to always have the last word.

Among the first to have his knuckles rapped was Sen. John McCain (Ariz.). The 2008 Republican presidential nominee accused his former rival of “unsavory” dealmaking, of breaking his promise to put health-care negotiations on C-SPAN, of supporting a 2,400-page bill, of giving favors to lobbyists and special interests. He directed Obama to “go back to the beginning” with health-care reform.

“Let me just make this point, John,” the president said when the tirade ended. “We’re not campaigning anymore. The election’s over.” Teacher directed student to drop the “talking points” and “focus on the issues of how we actually get a bill done.”

It’s a safe bet that no minds were changed in that room Thursday, and it’s not entirely clear that Obama was even trying to forge a compromise. Though advertised as a consensus-building opportunity, the summit served more as a moment for the president to tell Republicans, with the cameras rolling, why they’re wrong and he’s right.

The forum matched his lawyerly skills — and, less flatteringly, his tendency to act like the smartest guy in the room. Prof. Obama ventured deep into the weeds of health-care policy to contest Republican claims, and, for one day at least, he regained control of the fractious student body that is the Congress.

The 40 lawmakers and administration officials, seated in squeaky chairs around the square, were to speak only when called on. After each talked, Obama would determine whether the speaker’s point was a “legitimate argument.”

While each of them had to call him “Mr. President,” Obama, often waving an index finger, made sure to refer to each of them by their first name: “Thank you, Lamar. . . . We’re going to have Nancy and Harry. . . . John, are you going to make the presentation yourself?”

If somebody went on too long, Obama cautioned the lawmaker to be “more disciplined.” When Rep. Dave Camp (R-Mich.) spoke about Medicare cuts, Obama cut him off. “I don’t mean to interrupt,” he said, but “if every speaker, at least on one side, is going through every provision and saying what they don’t like, it’s going to be hard for us to see if we can arrive at some agreements.”

After several such moments, Senate Minority Leader Mitch McConnell (R-Ky.) spoke up. “Republicans have used 24 minutes; the Democrats, 52 minutes,” he said.

Obama made McConnell look small in his chair. “You’re right, there was an imbalance on the opening statements,” he said, “because I’m the president.”

The forum probably didn’t alter the trajectory of health-care legislation, if only because few Americans could possibly have paid attention.

In between the flare-ups, the summit was often the kind of event only a member of the Party of NoDoz could enjoy. Republicans numbingly repeated their demand that Obama “start over.” Democrats responded with their talking point that the parties are “not that far apart.” Both sides trotted out stories of afflicted Americans, including a woman who said she couldn’t afford dentures so she “wore her dead sister’s teeth.” And the vice president’s idle brain coined a new Bidenism when he said of his fellow Americans: “I’m not sure what they think.”

Yet there was something uplifting about Thursday’s session. Sure, there was more posturing than in a typical yoga class, but lawmakers demonstrated themselves to be serious and knowledgeable leaders as they treated the nation to a discussion about expanding high-risk insurance pools, 60 percent actuarial values and the like. It couldn’t hurt Americans to see their leaders arguing substantive points without scripts and attacks.

“Never have so many members of the House and Senate behaved so well for so long before so many television cameras,” Rep. Joe Barton (R-Tex.) observed.

That’s probably because their teacher carried a big rhetorical paddle.

After Sen. Lamar Alexander (R-Tenn.) accused Obama of trying to increase health-care premiums, Obama dismissed the “usual critique” of reform and told him that “this is an example of where we’ve got to get our facts straight.”

When Sen. Jon Kyl (R-Ariz.) said the two parties disagree about the question “Does Washington know best?” Obama shot back: “Anytime the question is phrased as ‘Does Washington know better?,’ I think we’re kind of tipping the scales. . . . It’s a good talking point, but it doesn’t actually answer the underlying question.”

Spotting a huge stack of papers in front of House Minority Whip Eric Cantor (R-Va.), Obama preempted him: “Let me guess: That’s the 2,400-page health-care bill.” It was. “These are the kind of political things we do that prevent us from actually having a conversation,” the president said.